Geared Crank-Frame Churn: A Frame Over an Ordinary Churn Gears a Hand Crank Up to Drive a Grated Dasher by Pitman

"The nature of my invention consists in providing a frame with suitable gearing to communicate a reciprocating motion to which the dasher of an ordinary churn can be attached or detached with facility, the whole forming a churn which can be worked to great advantage by a laborer by means of a crank."

From pine lumber 40 x 80 mm cut two uprights 570 mm long and a top bar 380 long, and join them 300 mm apart inside. Rout a groove 12 x 42 mm down the inside of each upright for the sash. Stand the frame on two rails and four legs 400 tall, the rails across the bucket's place so the frame stands over it. Screw a hardwood strap 60 x 20 mm upright behind the frame's middle, with a cross piece near its foot, and bore it 16.6 mm for the shafts c and d, 75 mm apart, 400 and 475 mm above the frame's foot.

Pass a 16 mm stainless shaft c through the upper hole with the wheel w on its front end and a hardwood crank k 140 mm long with a dowel handle on its back end. Pass a short 16 mm shaft through the lower hole with the pinion p meshing w, and in front of it a hardwood crank d with a 12 mm stainless pin 40 mm from the shaft. Hold both with collars.

Cut a hardwood pitman 20 x 10 mm with 12.6 mm holes 220 mm apart. Cut a hardwood sash 320 x 40 x 40 mm with tongues on its ends to slide in the grooves; bore it 22.6 mm through the middle for the dasher rod, slot its front for the pitman, and pin the pitman in the slot. Drill and tap a hole through the sash's back into the bore, or set a nut in it, and run in a short piece of threaded rod with a wing nut as the set screw i.

Glue a 22 mm hardwood dowel 555 mm long into the printed grate's centre, and cut a 28 mm hole in the centre of the bucket's lid for it.

Pour about 8 litres of heavy cream at about 15 °C, checked with the thermometer, into the bucket and put on the lid. Stand the frame over it, pass the dasher down through the sash into the bucket, set it so it just clears the floor at the bottom of the stroke and tighten the set screw. Turn the crank k steadily, timing it. When the butter comes, loosen the set screw and lift the dasher out, take out the butter, pour the buttermilk into a bowl, wash the butter in cold water until it runs clear, salt and weigh it.

**J. W. Evans** of Forsyth, Monroe County, Georgia, US 28,462, 29 May 1860, "Churn". He did not claim churn dashers worked by a crank nor the grated dasher, "as they are old and well known", but the arrangement with the grated dasher, sash and set screw. His frame is arched and on curved legs, and his wheel and pinion are drawn face-toothed; ours are spur gears on a strap behind a straight frame. Every size is ours.